Automatic fire and burglar alarm



No. 623,-44l. Patented Apr. l8, I899.

H. E. THOMPSON.

AUTOMATIC FIRE AND BUBGLAR ALARM.

(Application filed Apr. 16, 1898.)

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WITNESSES: INVENTOR M L A Hen U T/ronyson,

4A1 Am llnrrnn rates PATENT @rricm HENRY E. THOMPSON, OFCAMERON, NORTHCAROLINA.

AUTOMATIC FIRE AND BURGLAR ALARM.

SPECIFICATION formingpart of Letters Patent No. 623,441, dated April 18,1899.

Application filed April 16, 1898. serial No. 677,803. (No model.)

To all whom it may concern:

Be it known that 1, HENRY E. THOMPSON, a citizen of the United States ofAmerica, and a resident of Cameron, county of Moore, State of NorthCarolina, have invented a new and useful Improvement in Automatic Fireand Burglar Alarms, of which the following is a specification.

My invention relates to an automatic fire and burglar alarm system foruse especially in large buildings like hotels and office-buildings orfactories.

The object of the invention is to produce such a system that upon theoccurrence of a fire in any room or forcible entrance into the room by aburglar an alarm will almost immediately be given automatically to theoccupant and at the office, where there will be given also anannouncement of the number of the room. The object is further to make aninvent-ion by which although an alarm is given only in that room wherethere is a fire, yet the operator at the office maysend a current whichwill cause an alarm of fire in every room. The organization comprises anelectric bell in a shunt-circuit to an easily-fusible and low-resistanceconductor, both the bell and the resistance-conductor being located ineach room. This fusible conductor extends all around the room, so as tobe in the neighborhood of the heat produced by the initial fire. Theresistance of the electric-bell magnet is purposely high, and theelectric bell is so proportioned-that. upon an increase of current thebell will ring. I provide automatic means so that when the fuse breaksand the high resistance of a bell is alone in circuit the diminishedcurrent caused thereby partially deenergizes a relay-magnet. A localcircuit including an electric bell is thereby closed and the bell ringsin the office. The operator throws in additional battery for theelectric bells in the rooms of sufficient strength to overcome theirresistances and to ring them, their own battery being always too weakfor this purpose while the principal part of the current is passingthrough the fusible wire.

In order to understand the invention in all its details, drawings areannexed and described.

Figure 1 is a diagram of the complete system. Fig. 2 is a section of aroom, showing the fusible wire arranged around it and arranged to givean alarm when the door is opened. Fig. 3 shows a modification of aswitch .for including an extra battery in parallel circuit with theother instead of in series.

a represents the electric bells, located, re: spectively, in the roomsof a building. The fusible conductors form loops around the bells. Thesemay consist each of a continuous easily-fusible wire or of short piecesof copper wire soldered or otherwise fastened together by easily-fusiblemetal.

0 is a battery for the bells a, which are in series circuit.

d is a relay-magnet included in the circuit of the battery 0, which isalways closed. The magnet-(l therefore holds open the circuit closer eof the local circuit having the battery fand the hello. This magnet disof such a resistance that the circuit-closer 6 will fall away and closethe local circuit g when the current in the main circuit of the battery0 is made less by the rupture of the low-resistance conductor 2). Hencethe bell a will ring at the office when any conductor?) melts.

his a circuit-closer for the battery 0, normally closing said circuit atthe terminals *6, and it is suspended by an insulator which carries andseparates the terminals j of the extra battery 70.

' When the clerk in the office hears the alarm a and feels confidentthat it is because of a fire, in a manner hereinafter set forth he movesthe terminals j to the terminals 1', thereby opening the circuit-closerh and including the battery 7a in series with the battery 0.

.He need be in no doubt, for the annunciator will'indicate the roomwhence the alarm was sent for the following reasons: At Ais a magnet inseries with one of the bells a and in shunt to one of the fusible wiresZ2. When the latter breaks, the magnet A attracts the armature B andcloses the circuit ofthe battery C through the annunciator D. A modifiedautomatic circuit-closer for the annunciator is the extension E on thevibratory part of the bell a in circuit With the annunciator D, so thatthe circuit of the battery 0 will be closed when the bell rings. Afurther modification is the low-resistance magnet F in circuit with oneof the fusible wires 1), and

therefore normally energized and holding the armature-circuit closer Gopen. When the fuse breaks, the annunciator operates because thecircuit-closer G is in circuit with the battery G.

In order that the occupant of the room may ring for ice, hot water, andother articles, the push-button 0 is provided in the annunciatorcircuit.

In Fig. 3 the battery it is shown adapted to be placed in parallel withthe battery 0 by a switch 1, movable to be in contact with the terminalit alone of the main line or in circuit also with the terminal m of thebattery 70, the other end of the circuit-closer Z being connectedpermanently to the battery 0.

I claim as myinvention- 1. In an automatic fire and burglar alarmsystem, the combination of electric alarms in the respective rooms of abuilding of definitely high resistance, a fusible conductor of lowresistance forming a loop around each alarm, and including in itscircuit a circuitcloser operated by a door, Window or other movableobject, a battery for feeding the electric alarms, and normally closedthrough the same, a relay in circuit with said battery, a localalarm-circuit at the office of the build-' ing controlled by said relay,an extra battery, means for including said extra battery in circuit withthe other battery, an annunciator in the said ofiice, and means,controlled automatically by the breaking of a fuse, for operating saidannunciator.

2. In a fire-alarm system, the combination of a battery, a main-lineconductor normally energized by said battery, electric alarms includedin circuit with said conductor and said battery, fusible conductors incircuits that are shunt to said alarms, an office-alarm controlled andoperative by the breaking of any of said fuses, a second battery, andmeans for manually introducing said second battery into the circuit ofthe other battery.

Signed this 5th day of April, 1898.

HENRY E. THOMPSON. [L. s.]

Witnesses: i

M. MoL. MCKINTHEN, LIZZIE B. OULBERsoN.

